Crucifixion of St Peter (south wall, left)

On the south wall, in the Crucifixion of St Peter and the Beheading of St Paul, the foreground of each picture is reserved for its respective martyr. Each is, moreover, clearly larger than the figures of the mourners and the executioner. Peter, hanging upside down on the cross, recalls the crucifixes of Giunta Pisano and Cimabue in the rendering of his abdomen and chest musculature. In the background of the crucifixion scene are groups of buildings and single buildings. However, they are rather unspecific.